Clonal analysis of the cytolytic T-cell response to human tumors.

A variety of cloning techniques are being applied to the analysis of phenotype, specificity and mechanism of action of cytolytic T cells on autologous tumor cells. Technical factors are influencing the results and interpretation of these studies but, as Andrea Anichini and colleagues show here, this analysis has revealed that the cytotoxic response can be multiclonal, mediated by multiple mechanisms and directed to different groups of determinants expressed on the same tumor cells.